Insect control

ABSTRACT

Long chain aliphatic carbonyl compounds having mono-unsaturation at position C-2,3 which are useful for the control of insects.

I United States Patent 1 [111 3,728,395 Henrick et al. Apr. 17, 1973INSECT CONTROL [56] References Cited [75] Inventors: Clive A. Henrick;John B. Siddall,

both of Palo Alto, Calif. OTHER PUBLICATIONS [73] Assigneez Z onCorporation, Palo Alto Kolognvova et 21., Chem. Abstracts 52, 19,929g

Calif. (1958)- Filed: 1971 Primary Examiner-Daniel D. Horwitz [21] Appl.129 217 Attorney-Donald W. Erickson 521 US. Cl. ..260/594, 260/593 H,260/593 R, [57] ABSTRACT 26 260/4 260/473 260/476 R, Long chainaliphatic carbonyl compounds having 260/482 R, 260/486 R, 260/487,260/488 mono-unsaturation at position C-2,3 which are useful I 511 lm.CI. ..C07c 49/20, C07c 49/24 f the comm; ofinsem [58] Field of Search..260/594 7 Claims, No Drawings INSECT CONTROL This invention relates tomono-unsaturated aliphatic carbonyl compounds of formula A, preparationthereof and the control of insects. The aliphatic carbonyl compoundsuseful for the control of insects according to the present invention arerepresented by the following formula A:

wherein, each of R, R R, R and R is lower alkyl and X is hydrogen,bromo, chloro, fluoro or the group OR in which R is hydrogen, loweralkyl or carboxylic acyl.

The term lower alkyl, as used herein, refers to an alkyl group having achain length of one to six carbon atoms.

The compounds of formula A are prepared according to the followingoutlined synthesis:

In the practice of the above synthesis, a ketone of formula I isconverted into the saturated ketone or substituted ketone of formula II.The dihydro of I is formed by hydrogenation using palladium on carbon,or the like. The halides of formula II are prepared by treatmerit of theunsaturated compound I with dry hydrogen halide in an organic solventsuch as a chlorinated hydrocarbon. The compounds of formula II wherein Xis the group OR in which R is hydrogen are prepared by the addition ofwater to the olefinic bond of a compound of formula I using a mercuricsalt followed by reduction of the oxymercurial intermediate in situ.Suitable mercuric salts include mercuric acetate, mercuric nitrate,mercuric trifluoroacetate, mercuric acylates and mercuric halides.Suitable reducing agents include the borohydrides, hydrazine and sodiumamalgam. See Brown and Rei, J. Am. Chem. Soc. 91, 5646 (1969); Brown etal., J. Am. Chem. Soc. 89, 1522 and 1524 (1967); and Wakabayashi,J. Med.Chem. l2, l9] (January, 1969). By conducting the reaction in thepresence of an alcohol (R-OH) such as methanol, ethanol, isopropylalcohol, benzyl alcohol, cyclopentanol, and the like, the correspondingether is prepared. The compound of formula II wherein R is carboxylicacyl are prepared from a compound of formula I! wherein R is hydrogen byreaction with a carboxylic acid chloride or bromide or carboxylic acidanhydride in pyridine or by treatment with a carboxylic acid anhydridein the presence of sodium acetate. The reaction is generally conductedat a room temperature to reflux temperature for about I to 48 hours,shorter reaction time being favored by temperatures above roomtemperature.

A compound of formula II is then reacted with a phosphonate anion of theformula wherein R is lower alkyl using Emmons-Wadsworth conditions toprepare a carbonyl of formula A.

The following examples are provided to illustrate the practice of thepresent invention. Temperature is given in degrees Centigrade.

EXAMPLE 1 A. A suspension of 0.5 g. of 5 percent palladium-oncarboncatalyst in 50 ml. of ethanol is hydrogenated for 30 minutes. A solutionof 2 g. of 6,10-dimethyldodec-9- en-2-one in ml. of ethanol is added andhydrogenated with agitation until the theoretical amount of hydrogen hasbeen absorbed. The catalyst is then removed by filtration and thesolution is evaporated to yield 6,lO-dimethyldodecan-Z-one.

In 9,10same way, each of 6,l0-dimethylundecan-2- one,6-ethyl-lO-methyldodecan-Z-one, 6-methyl-l0- ethyldodecan-Z-one and6-methyl-l0-ethyltridecan-2- one is prepared by hydrogenation of therespective 9,20-dehydio precursor.

B. To 1.0 g. of a 57 percent dispersion of sodium hydride in oil isadded pentane. The pentane is removed and sodium hydride washed severaltimes with pentane. To the washed sodium hydride is added 4.6 g. ofdiethylacetylmethylphosphonate in 20 ml. of tetrahydrofuran at l0 underargon. After several minutes, the solution is transferred to a solutionof 2.0 g. of 6,lO-dimethylundecan-2-one in about 15 ml. of drytetrahydrofuran under argon over a period of about 20 minutes at roomtemperature. After about 24 hours, water is added followed by additionof ether and the layers separated. The organic layer is washed withsaturated sodium chloride, dried over sodium sulfate, and evaporatedunder reduced pressure to yield 4,8,12- trimethyltetradec-3-en-2-one.

By use of the above process, each of 4,8,12- trimethyltridec-3-en-2-one,4,1 2-dimethyl 8-ethyltetradec-3-en-2-one, 4,8-dimethyll2-ethyltetradec-3- en-2-one, and 4,8-dimethyl-l2-ethylperitadec-3-en-2-one is prepared from the respective precursor of part A above.

The process of part B is repeated with the exception of using diethylpropionylmethyl-phosphonate in place of diethyl acetyl-methylphosphonateto prepare the respective ethyl ketones, i.e.,

5 ,9,] S-trimethylpentadec-4-en-3one,

5 ,9. l 3trimethyltetradec-4-en-3-one,

5,13dimethyl9-ethylpentadec-4-en-3one,

5,9-dimethyll 3ethylpentadec-4-en3-one, and 5,9-dimethyll3-ethylhexadec-4-em3one, respectively.

EXAMPLE 2 A. To a solution of 1.7 g. of 6,10-dimethyldodec-9- en-2one in20 ml. of ethanol, cooled to 0 by an ice bath, is added a suspension-of2.3 g. of mercuric acetate in 50 ml. of ethanol over about 15 minutes.The reaction mixture is stirred for 2 hours and then, with cooling,1.2g. of potassium hydroxide in 20 ml. of ethanol is added. Then 0.139g. of sodium borohydride is added in small portions and stirringcontinued for 30 minutes. The solution is decanted, then concentrated tohalf volume, diluted with 100 ml. of water and extracted with ether. Theethereal phase is washed with water, dried over magnesium sulfate andthe crude product chromatographed on silica to yield lO-ethoxy- 6,1O-dimethyldodecan-Z-one.

Using the above process, each of l-ethoxy-6,l0- dimethylundecan-Z-one,IO-ethoxy-G-ethyl-lO-methyldodecan-Z-one, -ethoxy-6-methyllO-ethyldodecan- 2-one, and l0-ethoxy-6,l0-ethyltridecan-2-one isprepared from 6,10-dimethylundec-9-en-e-one, 6- ethyl-l0-methyldodec-9-en-2-one, G-methyll O-ethyldodec-9-en-2-one and6-methyl-l0-ethyltridec-9-en-2- one, respectively.

By using other lower monohydric alcohols (R-OH) in the foregoing processsuch as methanol, the corresponding lower alkoxy derivatives areobtained, e.g.,

l0-methoxy-6, l O-dimethyldodecan-Z-one,

l0-methoxy-6, l O-dimethylundecan-Z-one, etc.

B. By use of. the process of Example 1(B), diethylacetylmethylphosphonate is reacted with the alkoxy substituted ketonesof part A of this example to prepare the respective methyl ketones,e.g., 12-ethoxy-4-8,l2- trimethyltetradecqil-en-2-one, l2-ethoxy-4,8,12-trimethyltridec-3-en-2-one, l2-ethoxy-4, l 2-dimethyl-8-eth'yltetradec-3-en-2-one, l 2-ethoxy-4,8-dimethyl-12-ethyltetradec-3-en-2-one, l2-ethoxy-4,8-dimethyll 2-ethylpentadec-S-en-Z-one, l2-methoxy-4,8,12-trimethyltetradec-3-en-2-one, and l2-methoxy-4,8,l2-trimethyltridec-3-en-2 one, respectively.

In the same way, following the process of part B of Example 1, diethylpropionylmethylphosphonate is reacted withthe substitued ketones of partA of this example to prepare the respective ethyl ketones, i.e.,

l3-ethoxy-5 ,9,1 3-trimethylpentadec-4-en3-one,

l 3-ethoxy-5,9, 1 3-trimethyltetradec-4-en-3-one,'

l3-ethoxy-5 l 3-dimethyl-9-ethylpentadec-4-en-3- l3 :tiioxy-5,9-dimethyl-l 3-ethylpentadec-4-en-3- lBfifioxy-S,9-dimethyl-13-ethylhexadec-4-en-3- l3 r?1 e th0xy-5 ,9,l3-trimethylpentadec-4-en-3 -one, IIZSIiIhOXy-S ,9, l3-trimethyltetradec-4-en-3-one.

EXAMPLE 3 A. To a mixture of 1.9 g. of mercuric acetate, 6 ml. of waterand ml. of tetrahydrofuran is added 1.2 g. of6,lO-dimethyldodec-9-en-2-one slowly. After addition is complete, thereaction mixture is stirred for about 20 minutes. The mixture is cooledto about 0 and 6 ml. of aqueous sodium'hydroxide (SM) is added followedby 0.5 g. of sodium borohydride in aqueous sodium hydroxide (about 3M).The mixture is stirred for about 30 minutes. The mixture is thendecanted, concentrated, diluted with water and then extracted withether. The ethereal extract is washed with water, dried over magnesiumsulfate and the product chromatographed to yieldl0hydroxy-6,10-dimethyldodecan-2- one.

Each of l0-hydroxy-6,lO-dimethylundecan-Z-one, l0-hydroxy-6-ethyl- 10-methyldodecan-2-one, l0- hydroxy-6-methyl-IO-ethyldodecan-Z-one and10- hydroxy-6-methyl-lO-ethyltridecan-Z-one is prepared from therespective 9,10-dehydro precursor using the above process.

Following the procedure of Example 1(B), each of The compounds offormula A are useful for the control of insects. The compounds areapplied using either liquid or solid carriers, such as water, acetone,cottonseed oil, xylene, mineral oil, silica, talc, natural and syntheticresins, and the like. Generally, compositions for application willcontain upto about percent of the active compound and more usually lessthan 25 percent, sufficient composition should be applied to providefrom about 0.01v or less to 25 micrograms of the active compounds perinsect. Typical insects controlled by the present invention are Diptera,such as mosquitos and houseflies; Hemiptera, such as Pyrrhocoridae andMiridae; Homoptera, such as Aphids, Lepidoptera; and Coleoptera, such asTenebrionidae, Crysomelidae and Dermestidae. For example, Pyrrhocorisapterus, Lygus hesperus, Tenebrio molitor, Triboleum confusm, Diabroticaduodecimpunctam, Dermestes maculatus, Aedes aegypti, Musca domestica androaches. Without any intention of being bound by theory, the compoundsofformula A- are not believed to be' effective by reason of causingimmediate death, but rather the compounds of formula A are effective byreason of physiological changes caused in the treated insect whichresult in eventual death of the insect and/or inability of the treatedinsect to reproduce byreason of sterility or abnormal development.-

EXAMPLE 4 The process of Example K8) is repeated with the exception thatafter addition of 6,10-dimethylundecan-2- one is complete, the reactionmixture is refluxed overnight and 'then worked up to yield4,8,l2-trimethyltetradec-S-en-Z-one.

What is claimed is:

d l. A compound selected from those of the following formula A:

lower alkyl and'R is methyl or ethyl.

5. A compound according to claim 4 wherein R is lower alkyl of one tothree carbon atoms.

6. A compound according to claim 5 wherein R is methyl.

7. A compound according to claim 1 which is 12- ethoxy4,8 lZ-trimethyltridec-3-en-2-one.

2. A compound according to claim 1 wherein each of R1, R2, R3 and R4 ismethyl or ethyl.
 3. A compound according to claim 1 wherein R ishydrogen and R5 is methyl or ethyl.
 4. A compound according to claim 1wherein R is lower alkyl and R5 is methyl or ethyl.
 5. A compoundaccording to claim 4 wherein R is lower alkyl of one to three carbonatoms.
 6. A compound according to claim 5 wherein R1 is methyl.
 7. Acompound according to claim 1 which is12-ethoxy-4,8,12-trimethyltridec-3-en-2-one.